bug in route tables handling triggered by ppp

[Francis Gudin]

On 13-03-2006, Simon 'corecode' Schubert <corecode at xxxxxxxxxxxx> wrote:
>
> could you please post such things nevertheless on the mailing lists,=20
> even if just for archiving purposes.
>
> thanks
>    simon

Yep, here's a wild snarf/paste from gobsd:

I worked around an annoying bug this morning by cleaning up my ppp.conf.
As my only storage is ips, i can't provide any dump; hence, i decided to
post this here instead of bothering the developpers with an almost
useless bug-report. It's a bit of a reminder, and i also wish it could
avoid a nervous breakdown to anyone facing the same problem, maybe. Now
the story:

My system is a dual-cpu, DragonFly 1.5.1 and i use userland ppp in PPPoE
mode. When booting from my -DEVELOPMENT slice, i regularly experimented
panics (something like 1 out of 20 boots) and inconsistencies with the
route tables (default route entries missing because ppp couldn't "add
default HISADDR"). Until now, i just did this on startup:route delete
default && route add default -interface tun0
This morning, i decided to have a look closer at this issue. The problem
was that in single-user mode, panic'ing was 1/1 ! If this may help,
here's a transcript:
#/etc/rc.d/ppp-user start
Starting ppp as "root"
Warning: Add! route failed: ff02:: errno: Operation not supported
Warning: tun0: AIFADDR 213.41.166.51 -> 10.0.0.2 returns 0
#panic: rtrequest1_msghandler: rtrequest table error was not on CPU #0:
Note: panic took place two seconds after the shell prompted again.
db> trace
Debugger(c02cc075) at Debugger+0x3d
panic(c02d2b07,c9390c5c,0,c5c9fa00,ff808000) at panic+0x162
rtrequest1_msghandler(c9390c5c) at rtrequest1_msghandler+0x83
rtable_service_loop(0,0,0,0,0) at rtable_service_loop+0x13
lwkt_exit() at lkwt_exit

At complete random, i had a look at ppp(8) and found my set ifaddr line
quite wrong:
set ifaddr 213.41.166.51 10.0.0.2 255.255.255.0 0.0.0.0
After fixing that to:
set ifaddr 213.41.166.51 62.4.16.246 255.255.255.255 213.41.166.51
i no longer see panics, even in the 100% reproductible case (single-user
mode), and my route tables are ok. ppp properly adds default routes (i
have a native ipv6 link, thanks Nerim!), though it still warns about the
"ff02::" route entry, which i'll investigate later on.

If anyone really want it thoroughly debugged, i can provide informations
with kgdb instead of a dump, just let me know.

Francis.